Head mounted display device

ABSTRACT

A head mounted display device is provided. The head mounted display device includes a left eye display unit which displays an image for a left eye and is disposed along a trajectory of a left eye ellipse having a first eccentricity, and a left eye lens which faces the left eye display unit and refracts the image for the left eye in a direction of a user&#39;s left eye.

This application is a divisional of U.S. patent application Ser. No.15/982,789, filed on May 17, 2018, which claims priority to KoreanPatent Application No. 10-2017-0079117, filed on Jun. 22, 2017, and allthe benefits accruing therefrom under 35 U.S.C. § 119, the content ofwhich in its entirety is herein incorporated by reference.

BACKGROUND 1. Field

Exemplary embodiments of the invention relate to a head mounted displaydevice.

2. Description of the Related Art

A head mounted display (“HMD”) device, which is mounted on a head todisplay an image to a user, has recently attracted a considerableattention as a visualization device for providing a virtual reality oran augmented reality.

A head mounted display device generally includes a display plate fordisplaying an image and a lens disposed between the display plate and auser's eyeball to magnify an image and refract the magnified image tothe user's eyeball.

SUMMARY

A head mounted display device, unlike a conventional display device, isproblematic in that a user recognizes a virtual image due to a lensdisposed between a display plate and user's eye. Such a virtual image,which is recognized by allowing light reflected by the lens to beincident on the user's eye again to be recognized by the user, hascaused a problem of deteriorating a display quality of the head mounteddisplay device.

Accordingly, in order to solve the above problem, exemplary embodimentsof the invention provide a head mounted display device, which mayminimize the phenomenon of a virtual image caused by the reflected lightdue to a lens being recognized by a user.

According to an exemplary embodiment of the invention, there is provideda head mounted display device. The display device includes a left eyedisplay unit which displays an image for a left eye and is disposedalong a trajectory of a left eye ellipse having a first eccentricity,and a left eye lens facing the left eye display unit and which refractsthe image for the left eye in a direction of a user's left eye.

According to another exemplary embodiment of the invention, there isprovided a head mounted display device. The display device includes adisplay unit including a first portion which displays an image for aleft eye and is disposed along a trajectory of a left eye ellipse havinga first eccentricity, a second portion which displays an image for aright eye and is disposed along a trajectory of a right eye ellipsehaving a second eccentricity, and a third portion between the firstportion and the second portion, a left eye lens which faces the firstportion and refracts the image for the left eye in a direction of auser's left eye, and a right eye lens which faces the second portion andrefracts the image for the right eye in a direction of a user's righteye.

According to another exemplary embodiment of the invention, there isprovided a head mounted display device. The display device includes aleft eye display unit which displays an image for a left eye and isdisposed along a trajectory of a left eye ellipse having a firsteccentricity, a right eye display unit which displays an image for aright eye and is disposed along a trajectory of a right eye ellipsehaving a first eccentricity, a left eye lens which faces the left eyedisplay unit and refracts the image for the left eye in a direction of auser's left eye, and a right eye lens which faces the right eye displayunit and refracts the image for the right eye in a direction of a user'sright eye, where the left eye ellipse defines a first left eye focus anda second left eye focus disposed away from the user's right eye than thefirst left eye focus, the right eye ellipse defines a first right eyefocus and a second right eye focus disposed away from the user's lefteye than the first right eye focus, the left eye lens overlaps the firstleft eye focus on a plane on which the left eye ellipse is disposed, andthe right eye lens overlaps the first right eye focus on a plane onwhich the right eye ellipse is disposed.

However, exemplary embodiments of the invention are not restricted tothe exemplary embodiments set forth herein. The above and otherexemplary embodiments of the invention will become more apparent to oneof ordinary skill in the art to which the invention pertains byreferencing the detailed description of the invention given below.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other exemplary embodiments, advantages and features ofthe invention will become more apparent by describing in detailexemplary embodiments thereof with reference to the attached drawings,in which:

FIGS. 1A and 1B are perspective views showing an exemplary embodiment ofa head mounted display device according to the invention;

FIG. 2 is a schematic view showing a part of a configuration of the headmounted display device shown in FIG. 1;

FIG. 3 is a sectional view of the head mounted display device shown inFIG. 2 taken along the plane on which a left eye ellipse and a right eyeellipse are disposed;

FIGS. 4 and 5 are sectional views showing an exemplary embodiment of aleft eye display unit and a left eye lens according to the exemplaryembodiment shown in FIGS. 2 and 3, respectively;

FIG. 6 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 7 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 8 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 9 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 10 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 11 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 4;

FIG. 12 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 13 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 3;

FIG. 14 is a sectional view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 2;

FIG. 15 is a schematic view of another exemplary embodiment of a headmounted display device at a point corresponding to the point of FIG. 2;and

FIG. 16 is a sectional view of the head mounted display device shown inFIG. 15 taken along the plane on which a left eye ellipse and a righteye ellipse are disposed.

DETAILED DESCRIPTION

The invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied indifferent forms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fillyconvey the scope of the invention to those skilled in the art. The samereference numbers indicate the same components throughout thespecification. In the attached drawing figures, the thickness of layersand regions is exaggerated for clarity.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another element. Thus, a first elementdiscussed below could be termed a second element without departing fromthe teachings of the invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the drawing figures. It will be understoodthat the spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the drawing figures. For example, if the devicein the drawing figures is turned over, elements described as “below” or“beneath” other elements or features would then be oriented “above” theother elements or features. Thus, the exemplary term “below” canencompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In the invention, an electronic apparatus may be any apparatus providedwith a display device. Examples of the electronic apparatus may includesmart phones, mobile phones, navigators, game machines, TVs, car headunits, notebook computers, laptop computers, tablet computers, personalmedia players (“PMPs”), and personal digital assistants (“PDAs”). Theelectronic apparatus may be embodied as a pocket-sized portablecommunication terminal having a wireless communication function.Further, the display device may be a flexible display device capable ofchanging its shape.

Hereinafter, embodiments of the invention will be described withreference to the attached drawings.

FIGS. 1A and 1B are perspective views showing a head mounted displaydevice according to an exemplary embodiment of the invention.

As shown in FIGS. 1A and 1B, the head mounted display device accordingto an exemplary embodiment of the invention is mounted on a user's headto display an image LI for a left eye and an image RI for a right eye touser's eyes, respectively, and includes a case CS and a wearing unit WUconnected to the case CS.

The case CS may be worn on at least a part (for example, facial side) ofa user's face, and may be supported to a facial side of a user byvarious components. The inside of the case CS may accommodate andsupport a left eye display unit LD, a right eye display unit RD, a lefteye lens LLS (refer to FIG. 2), and a right eye lens RLS (refer to FIG.2), which will be described later. The case CS may be formed in anyshape as long as the case CS may be mounted on the user's head whilesupporting the left eye display unit LD, the right eye display unit RD,the left eye lens LLS, and the right eye lens RLS. In an exemplaryembodiment, the case CS may have various shapes, and, for example, mayhave an eyeglass shape or a helmet shape.

A housing HA is provided with a left eye opening LO through which animage LI for a left eye is displayed and a right eye opening RO throughwhich an image RI for a right eye is displayed. The image displayed onthe left eye display unit LD may be recognized by a user's left eye LEthrough the left eye opening LO via the left eye lens LLS, and the imagedisplayed on the right eye display unit RD may be recognized by a user'sright eye RE through the right eye opening RO via the right eye lensRLS. In an exemplary embodiment, when the left eye lens LLS and theright eye lens RLS are directly exposed to the outside of the case CS,the left eye opening LO and the right eye opening RO may be formed in avery thin width or may be omitted. In an exemplary embodiment, anotheropening (not shown) may be further provided in addition to the left eyeopening LO and the right eye opening RO. Through the another opening,the surrounding background may be visually checked at the same time inaddition to the displayed image when the left eye display unit LD andthe right eye display unit RD are transparent display units. Thisopening may be utilized to use an augmented reality or virtual realitytechnology.

Although not shown specifically, the image LI for a left eye, shown inthis drawing, may be an image having passed through the left eye lensLLS, and the image RI for a right eye, shown in this drawing, may be animage having passed through the right eye lens RLS.

The wearing unit WU fixes the case CS to a user's head. The wearing unitWU may include any shape or any material as long as the case CS may befixed to the user's head. In an exemplary embodiment, when the headmounted display device has an eyeglass shape, the wearing unit WU mayhave a leg shape of an eyeglass as shown in FIGS. 1A and 1B. In anexemplary embodiment, the wearing unit WU may have a band shapesurrounding the user's head.

FIG. 2 is a schematic view showing a part of a configuration of the headmounted display device shown in FIGS. 1A and 1B, and FIG. 3 is asectional view of the head mounted display device shown in FIG. 2 takenalong the plane on which a left eye ellipse and a right eye ellipse aredisposed.

The left eye ellipse EL1 and the right eye ellipse EL2 are disposed onthe same plane, and may be the same as each other in length of majoraxis, length of minor axis, and eccentricity. The left eye ellipse EL1and the right eye ellipse EL2 are not physically real components, butmay be virtual ellipses that define the relative positional relationshipof the respective components disposed inside the housing HA. The lefteye ellipse EL1 may be defined by Equation (1) below with respect to acoordinate plane having a major axis as the x axis, a minor axis as they axis, and a center point as the origin.

$\begin{matrix}{{\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}}} = 1} & {{Equation}\mspace{14mu} (1)}\end{matrix}$

Here, a may be a major radius of the left eye ellipse EL1, and b may bea minor radius of the left eye ellipse ELL The major radius may be ahalf of the major axis (that is, long diameter) of an ellipse, and theminor radius may be a half of the minor axis (that is, short diameter)of an ellipse.

The first eccentricity e1, which is an eccentricity of the left eyeellipse EL1, may be defined by Equation (2) below.

$\begin{matrix}{{e\; 1} = {\frac{\sqrt{a^{2} - b^{2}}}{a} = \sqrt{1 - \frac{b^{2}}{a^{2}}}}} & {{Equation}\mspace{14mu} (2)}\end{matrix}$

The eccentricity is a value indicating the degree of distortion of theellipse. As the eccentricity is closer to 0, the ellipse is closer to acircle. As the eccentricity is closer to 1, the ellipse has a moreseriously distorted shape (that is, shape having a short minor radius).

Similarly, the right eye ellipse EL2 may be defined by Equation (3)below with respect to a coordinate plane having a major axis as the xaxis, a minor axis as the y axis, and a center point as the origin.

$\begin{matrix}{{\frac{x^{2}}{c^{2}} + \frac{y^{2}}{d^{2}}} = 1} & {{Equation}\mspace{14mu} (3)}\end{matrix}$

Here, c may be a major radius of the right eye ellipse EL2, and d may bea minor radius of the right eye ellipse EL2.

The second eccentricity e2, which is an eccentricity of the right eyeellipse EL2, may be defined by Equation (4) below.

$\begin{matrix}{{e\; 2} = {\frac{\sqrt{c^{2} - d^{2}}}{c} = \sqrt{1 - \frac{d^{2}}{c^{2}}}}} & {{Equation}\mspace{14mu} (4)}\end{matrix}$

Here, the major radius a of the left eye ellipse EL1 may have the samevalue as the major radius c of the right eye ellipse EL2. Further, theminor radius b of the left eye ellipse EL1 may have the same value asthe minor radius d of the right eye ellipse EL2. In this case, theeccentricity e1 of the left eye ellipse EL1 and the eccentricity e2 ofthe right eye ellipse EL2 may have the same value as each other. Inother words, the left eye ellipse EL1 and the right eye ellipse EL2 maybe ellipses having the same shape as each other. In this exemplaryembodiment, a configuration in which the left eye ellipse EL1 and theright eye ellipse EL2 have the same shape is illustrated, but, inanother exemplary embodiment, the left eye ellipse EL1 and the right eyeellipse EL2 may have different sizes and may have differenteccentricities.

The left eye ellipse EL1 may have two focuses. Here, the focus disposedclose to the user's right eye RE is referred to as a first left eyefocus LF1, and the other focus is referred to as a second left eye focusLF2. In other words, the focus disposed away from the user's right eyeRE is referred to as a second left eye focus LF2, and the other focus isreferred to as a first left eye focus LF1. Similarly, the right eyeellipse EL2 may have two focuses. Here, the focus disposed close to theuser's left eye LE is referred to as a first right eye focus RF1, andthe other focus is referred to as a second right eye focus RF2. In otherwords, the focus disposed away from the user's left eye LE is referredto as a second right eye focus RF2, and the other focus is referred toas a first right eye focus RF1. In this case, the major axis Lax1 of theleft eye ellipse may pass through the first left eye focus LF1 and thesecond left eye focus LF2, and the major axis Rax1 of the right eyeellipse may pass through the first right eye focus RF1 and the secondright eye focus RF2. Further, the short axis Lax2 of the left eyeellipse may pass through the center point of the left eye ellipse EL1,and may be orthogonal to the major axis Lax1 of the left eye ellipse.Similarly, the short axis Rax2 of the right eye ellipse may pass throughthe center point of the right eye ellipse EL2, and may be orthogonal tothe long axis Rax1 of the right eye ellipse.

The left eye ellipse EL1 may be divided into two regions. Specifically,the left eye ellipse EL1 may be divided into two regions by the majoraxis Lax1 of the left eye ellipse. In this case, the region located inthe direction in which the left eye display unit LD is disposed may bedefined as a first left eye ellipse region LR1, and the other region maybe defined as a second left eye ellipse region LR2. Similarly, the righteye ellipse EL2 may be divided into two regions. Specifically, the righteye ellipse EL2 may be divided into two regions by the major axis Rax1of the right eye ellipse. In this case, the region located in thedirection in which the right eye display unit RD is disposed may bedefined as a first right eye ellipse region RR1, and the other regionmay be defined as a second right eye ellipse region RR2.

Moreover, the second left eye ellipse region LR2 may be divided into tworegions. Specifically, the second left eye ellipse region LR2 may bedivided into two regions by the minor axis Lax2 of the left eye ellipse.In this case, the region disposed close to the left eye display unit LDmay be defined as a first sub left eye ellipse region LSR1, and theother region may be defined as a second sub left eye ellipse regionLSR2.

Similarly, the second right eye ellipse region RR2 may be divided intotwo regions. Specifically, the second right eye ellipse region RR2 maybe divided into two regions by the minor axis Rax2 of the right eyeellipse. In this case, the region disposed close to the right eyedisplay unit RD may be defined as a first sub right eye ellipse regionRSR1, and the other region may be defined as a second sub right eyeellipse region RSR2.

Here, the first sub left eye ellipse region LSR1 and the first sub righteye ellipse region RSR1 may be disposed adjacent to each other. In otherwords, the first sub right eye ellipse region RSR1 may be disposedcloser to the first sub left eye ellipse region LSR1 than the second subright eye ellipse region RSR2, and the first sub left eye ellipse regionLSR1 may be disposed closer to the first sub right eye ellipse regionRSR1 than the second sub left eye ellipse region LSR2.

The left eye ellipse EL1 and the right eye ellipse EL2 may be disposedso as to partially overlap each other. However, the invention is notlimited thereto, and, in an exemplary embodiment, the left eye ellipseEL1 and the right eye ellipse EL2 may be disposed to be spaced apartfrom each other.

The left eye ellipse EL1 and the right eye ellipse EL2 may be disposedto obliquely intersect each other. In other words, the major axis Lax1of the left eye ellipse and the major axis Rax1 of the right eye ellipsemay be disposed so as to intersect each other to form a predeterminedangle therebetween.

Hereinafter, a head mounted display device according to an exemplaryembodiment of the invention will be described.

Referring to FIGS. 2 and 3, the head mounted display device according toan exemplary embodiment of the invention may include a left eye displayunit LD, a right eye display unit RD, a left eye lens LLS, and a righteye lens RLS.

Each of the left eye display unit LD and the right eye display unit RDincludes a plurality of pixels (not shown). Here, the pixel may mean aminimum unit for displaying a color. Each of the left eye display unitLD and the right eye display unit RD may include an organiclight-emitting diode (“OLED”) (not shown), and may further include atleast one scan wiring (not shown) for causing the an OLED to emit light,at least one data line (not shown), a plurality of thin film transistors(not shown), and at least one capacitor (not shown). However, the lefteye display unit LD and the right eye display unit RD may not be limitedto being composed of organic light emitting diodes. In some exemplaryembodiments, examples of the left eye display unit LD and the right eyedisplay unit RD may include various display devices, such as liquidcrystal displays (“LCDs”), plasma displays (“PDs”), field emissiondisplays (“FEDs”), electrophoretic displays (“EPDs”), and electrowettingdisplays (“EWDs”).

The left eye display unit LD and the right eye display unit RD may becomposed of different panels from each other. However, the invention isnot limited thereto, and, in some exemplary embodiments, the left eyedisplay unit LD and the right eye display unit RD may be composed of thesame panel.

The left eye display unit LD is disposed along the trajectory of theleft eye ellipse ELL and the right eye display unit RD is disposed alongthe trajectory of the right eye ellipse EL2. Here, the meaning that theleft eye display unit LD is disposed along the trajectory of the lefteye ellipse EL1 means that when a reflecting surface capable ofreflecting the light provided to the left eye display unit LD is cutalong the plane on which the left eye ellipse EL1 is disposed, thereflecting surface is disposed to be in contact with the left eyeellipse ELL and has a shape bent to have an eccentricity equal to thefirst eccentricity e1. This configuration may be applied to the righteye display unit RD, and the right eye display unit RD may have a curvedshape so as to have the second eccentricity e2.

Moreover, the left eye display unit LD may have a shape extending in adirection perpendicular to the plane on which the left eye ellipse EL1is disposed. That is, the left eye display unit LD may have a shape inwhich a part of the elliptical column defined by the left eye ellipseEL1 is removed. Similarly, the right eye display unit RD may have ashape extending in a direction perpendicular to the plane on which theright eye ellipse EL2 is disposed. In other words, the right eye displayunit RD may have a shape in which a part of the elliptical columndefined by the right eye ellipse EL2 is removed. Each of the left eyedisplay unit LD and the right eye display unit RD may have a height h.Here, the height of each of the left eye display unit LD and the righteye display unit RD may be referred to as a length extending in adirection perpendicular to the plane on which each of the left eyeellipse EL1 and the right eye ellipse EL2. The left eye display unit LDmay be bisected by the left eye ellipse EL1. In other words, the lefteye display unit LD may extend by h/2 along a direction perpendicular tothe plane on which the left eye ellipse EL1 is disposed and a directionopposite to the plane with respect to the plane. Similarly, the righteye display unit RD may be bisected by the right eye ellipse EL2. Inother words, the right eye display unit RD may extend by h/2 along adirection perpendicular to the plane on which the right eye ellipse EL2is disposed and a direction opposite to the plane with respect to theplane. However, the invention is not limited thereto, and the left eyedisplay unit LD may not be bisected by the left eye ellipse EL1, and theright eye display RD may not be bisected by the right eye ellipse EL2.

In order to prevent the left eye display unit LD from having anexcessively curved structure, the left eye display unit LD may bedisposed not to overlap the major axis Lax1 of the left eye ellipse. Inother words, the left eye display unit LD may be disposed to be spacedapart from the major axis Lax1 of the left eye ellipse. In order toprevent the right eye display unit RD from having an excessively curvedstructure, the right eye display unit RD may be disposed not to overlapthe major axis Rax1 of the right eye ellipse. In other words, the righteye display unit RD may be disposed to be spaced apart from the majoraxis Rax1 of the right eye ellipse.

The left eye lens LLS faces the left eye display unit LD, and magnifiesan image LI (refer to FIG. 1B) for a left eye, displayed by the left eyedisplay unit LD, and refracts the magnified image in the direction ofthe user's left eye LE. The front surface of the left eye lens LLS mayhave a convex shape toward the left eye display unit LD. However, theinvention is not limited thereto, and the front surface of the left eyelens LLS may have a concave shape or a planar shape. Here, among bothsurfaces of the left eye lens LLS, the front surface of the left eyelens LLS may be one surface disposed in the direction toward the lefteye display unit LD, and the rear surface of the left eye lens LLS maybe one surface disposed in the direction toward the user's left eye LE.The rear surface of the left eye lens LLS may have a convex shape, butthe invention is not limited thereto. In an exemplary embodiment, therear surface of the left eye lens LLS may have a concave shape or aplanar shape, for example. As shown in FIG. 3, first to third left eyelights LDL1 to LDL3, which are lights emitted by the left eye displayunit LD for each position, may pass through the left eye lens LLS, andmay be refracted and provided to the user's left eye LE.

Similarly, the right eye lens RLS faces the right eye display unit RD,and magnifies an image RI (refer to FIG. 1B) for a right eye, displayedby the right eye display unit RD, and refracts the magnified image inthe direction of the user's right eye RE. The front surface of the righteye lens RLS may have a convex shape toward the right eye display unitRD. However, the invention is not limited thereto, and the front surfaceof the right eye lens RLS may have a concave shape or a planar shape.Here, among both surfaces of the right eye lens RLS, the front surfaceof the right eye lens RLS may be one surface disposed in the directiontoward the right eye display unit RD, and the rear surface of the righteye lens RLS may be one surface disposed in the direction toward theuser's right eye RE. The rear surface of the right eye lens RLS may havea convex shape, but the invention is not limited thereto. In anexemplary embodiment, the rear surface of the right eye lens RLS mayhave a concave shape or a planar shape, for example. As shown in FIG. 3,first to third right eye lights RDL1 to RDL3, which are lights emittedby the right eye display unit RD for each position, may pass through theright eye lens RLS, and may be refracted and provided to the user'sright eye RE.

A blocking unit (not shown) may be disposed between the left eye lensLLS and the right eye lens RLS. The blocking unit may be a part of thehousing HA. The blocking unit may serve to prevent the image displayedon the left eye display unit LD from being recognized by the user'sright eye RE and to prevent the image displayed on the right eye displayunit RD from being recognized by the user's left eye LE.

The left eye lens LLS may be disposed so as to overlap the first lefteye focus LF1 on a plane on which the left eye ellipse EL1 is disposed.In other words, the left eye lens LLS may be disposed such that at leasta part of the section of the left eye lens LLS cut by the left eyeellipse EL1 overlaps the first left eye focus LF1. In this case, thephenomenon that the virtual image due to the reflected light of the lefteye lens LLS is recognized by the user's left eye LE may be minimized.Similarly, the right eye lens RLS may be disposed so as to overlap thefirst right eye focus RF1 on a plane on which the right eye ellipse EL2is disposed. In other words, the right eye lens RLS may be disposed suchthat at least a part of the section of the right eye lens RLS cut by theright eye ellipse EL2 overlaps the first right eye focus RF1. In thiscase, the phenomenon that the virtual image due to the reflected lightof the right eye lens RLS is recognized by the user's right eye RE maybe minimized.

The centroid LC of the left eye lens LLS may be disposed in the firstsub left eye ellipse region LSR1. Here, the centroid LC of the left eyelens LLS corresponds to the geometric center of the section of the lefteye lens LLS cut by the plane on which the left eye ellipse EL1 isdisposed. The centroid LC of the left eye lens LLS may have coordinatesof (Xlc, Ylc) on the coordinate plane assuming the center point of theleft eye ellipse EL1 as the origin, the major axis Lax1 of the left eyeellipse as the x axis, and the minor axis of the left eye ellipse Lax2as the y axis. The coordinates of the centroid LC of the left eye lensLLS may be calculated by Equations (5) and (6) below.

$\begin{matrix}{{Xlc} = {\frac{1}{A}{\int{xdA}}}} & {{Equation}\mspace{14mu} (5)} \\{{Ylc} = {\frac{1}{A}{\int{ydA}}}} & {{Equation}\mspace{14mu} (6)}\end{matrix}$

Here, A corresponds to the area of the section of the left eye lens LLS.

When the centroid LC of the left eye lens LLS is disposed in the firstsub left eye ellipse region LSR1, the phenomenon that the virtual imagedue to the reflected light of the left eye lens LLS is recognized by theuser's left eye LE may be minimized.

Similarly, the centroid RC of the right eye lens RLS may be disposed inthe first sub right eye ellipse region RSR1. Here, the centroid RC ofthe right eye lens RLS corresponds to the geometric center of thesection of the right eye lens RLS cut by the plane on which the righteye ellipse EL2 is disposed. The centroid RC of the right eye lens RLSmay have coordinates of (Xrc, Yrc) on the coordinate plane assuming thecenter point of the right eye ellipse EL2 as the origin, the major axisRax1 of the right eye ellipse as the x axis, and the minor axis of theright eye ellipse Rax2 as they axis. The coordinates of the centroid RCof the right eye lens RLS may be calculated by Equations (7) and (8)below.

$\begin{matrix}{{Xrc} = {\frac{1}{B}{\int{xdB}}}} & {{Equation}\mspace{14mu} (7)} \\{{Yrc} = {\frac{1}{B}{\int{ydB}}}} & {{Equation}\mspace{14mu} (8)}\end{matrix}$

Here, B corresponds to the area of the section of the right eye lensRLS.

When the centroid RC of the right eye lens RLS is disposed in the firstsub right eye ellipse region RSR1, the phenomenon that the virtual imagedue to the reflected light of the right eye lens RLS is recognized bythe user's right eye RE may be minimized.

The section of the left eye lens LLS cut by the left eye ellipse EL1 maybe disposed such that at least a part thereof overlaps the first subleft eye ellipse region LSR1. In this case, the phenomenon that thevirtual image due to the reflected light of the left eye lens LLS isrecognized by the user's left eye LE may be minimized. Similarly, thesection of the right eye lens RLS cut by the right eye ellipse EL2 maybe disposed such that at least a part thereof overlaps the first subright eye ellipse region RSR1. In this case, the phenomenon that thevirtual image due to the reflected light of the right eye lens RLS isrecognized by the user's right eye RE may be minimized.

FIGS. 4 and 5 are further referred to for a more detailed descriptionthereof.

FIGS. 4 and 5 are sectional views showing the left eye display unit andthe left eye lens according to the exemplary embodiment shown in FIGS. 2and 3.

FIG. 4 shows a path through which the light emitted from the left eyedisplay unit LD is reflected from the front or rear surface of the lefteye lens LLS, and FIG. 5 shows a path through which the light reflectedfrom the front or rear surface of the left eye lens LLS is reflected bythe left eye display unit LD and proceeds.

Referring to FIG. 4, the first left eye reflected light LRF1, which is apart of the light emitted from the left eye display part LD, may bereflected from the front surface of the left eye lens LLS and proceedtoward the left eye display unit LD again. In this drawing, any one ofthe optical paths reflected from the front surface of the left eye lensLLS is exemplified as the optical path of the first left eye reflectedlight LRF1, but, in practice, light reflection may occur at variousangles across all points on the front surface of the left eye lens LLS.

Further, although the second left eye reflected light LRF2, which isanother part of the light emitted from the left eye display unit LD, isrefracted at the front surface of the left eye lens LLS and normallyproceeds, the second left eye reflected light LRF2 may be reflected fromthe rear surface of the left eye lens LLS and proceed toward the lefteye display unit LD again. In this drawing, any one of the optical pathsreflected from the rear surface of the left eye lens LLS is exemplifiedas the optical path of the second left eye reflected light LRF2, but, inpractice, light reflection may occur at various angles across all pointson the rear surface of the left eye lens LLS.

When the first left eye reflected light LRF1 and the second left eyereflected light LRF2 are reflected again by the left eye display unit LDand proceed to the left eye lens LLS again to reach the user's left eyeLE, a blurred virtual image whose upper and lower and/or left and rightare reflected may be recognized by the user. Such a virtual image maydeteriorate display quality. However, since the light emitted from onefocus of an ellipse has a property of being reflected by the ellipse andproceeding to the other focus of the ellipse, the deterioration ofdisplay quality due to the virtual image may be minimized when thestructure of the invention is applied.

Specifically, as shown in FIG. 5, when the left eye lens LLS is disposednear the first left eye focus LF1 and the left eye display unit LD isdisposed along the left eye ellipse ELL the first left eye reflectedlight LRF1 and second left eye reflected light LRF2 reflected from thefront or rear surface of the left eye lens LLS may be reflected again bythe left eye display unit LD and then proceed toward the second left eyefocus LF2. That is, the first left eye reflected light LRF1 and secondleft eye reflected light LRF2 reflected by the left eye lens LLS may notbe provided to the user's left eye LE, and thus the user may notrecognize the virtual image.

Here, the meaning that the left eye lens LLS is disposed near the lefteye focus LF1 means that the left eye lens LLS is disposed to overlapthe first left eye focus LF1 of the left lens LLS on the plane on whichthe left eye ellipse EL1 is disposed, the centroid LC of the left eyelens LLS is disposed in the first sub left eye ellipse region LSR1, orat least a part of the section of the left eye lens LLS cut by the lefteye ellipse EL1 is disposed to overlap the first sub left eye ellipseregion LSR1.

Since the description with reference to FIGS. 4 and 5 may be applied tothe right eye display unit RD and the right eye lens RLS in the samemanner, this description will be omitted.

FIG. 6 is a sectional view of a head mounted display device according toanother exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 6, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 6, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD, a right eyedisplay unit RD, a left eye lens LLS_a, and a right eye lens RLS_a.

The left eye lens LLS_a may be disposed so as not to overlap the firstleft eye focus LF1, and the right eye lens RLS_a may be disposed so asnot to overlap the first right eye focus RF1. However, the centroid LC_aof the left eye lens LLS_a may be disposed in the first sub left eyeellipse region LSR1, and the centroid RC_a of the right eye lens RLS_amay be disposed in the first sub right eye ellipse region RSR1. In thecase of the exemplary embodiment described with reference to FIG. 3, theleft eye lens LLS overlaps the first left eye focus LF1 and the centroidLC of the left eye lens LLS is disposed in the first sub left eyeellipse region LSR1, and the right eye lens RLS overlaps the first righteye focus RF1 and the centroid RC of the right eye lens RLS is disposedin the first sub right eye ellipse region RSR1. However, unlike theexemplary embodiment described with reference to FIG. 3, in the case ofthis exemplary embodiment, even when the left eye lens LLS_a and theright eye lens RLS_a do not necessarily overlap the first left eye focusLF1 and the first right eye focus RF1, respectively, when the centroidRC_a of the left eye lens LLS_a and the centroid RC_a of the right eyelens RLS_a are disposed in the first sub left eye ellipse region LSR1and the first sub right eye ellipse region RSR1, respectively, theeffect of the invention may be obtained.

FIG. 7 is a sectional view of a head mounted display device according toanother exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 7, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 7, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD, a right eyedisplay unit RD, a left eye lens LLS_b, and a right eye lens RLS_b.

The centroid LC b of the left eye lens LLS_b may be disposed in thefirst sub left eye ellipse region LSR1, and the centroid RC_b of theright eye lens RLS_b may be disposed in the first sub right eye ellipseregion RSR1. However, the left eye lens LLS_b may be disposed so as tooverlap the first left eye focus LF1, and the right eye lens RLS_b maybe disposed so as to overlap the first right eye focus RF1.

In the case of the exemplary embodiment described with reference to FIG.3, the left eye lens LLS overlaps the first left eye focus LF1 and thecentroid LC of the left eye lens LLS is disposed in the first sub lefteye ellipse region LSR1, and the right eye lens RLS overlaps the firstright eye focus RF1 and the centroid RC of the right eye lens RLS isdisposed in the first sub right eye ellipse region RSR1. However, unlikethe exemplary embodiment described with reference to FIG. 3, in the caseof this exemplary embodiment, even when the centroid LC b of the lefteye lens LLS_b and the centroid RC_b of the right eye lens RLS_b are notnecessarily disposed in the first sub left eye ellipse region LSR1 andthe first sub right eye ellipse region RSR1, respectively, when the lefteye lens LLS_b and the right eye lens RLS_b overlap the first left eyefocus LF1 and the first right eye focus RF1, respectively, the effect ofthe invention may be obtained.

FIG. 8 is a sectional view of a head mounted display device according toanother exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 8, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 8, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD, a right eyedisplay unit RD, a left eye lens LLS, and a right eye lens RLS.

The left eye display unit LD may be disposed along the left eye ellipseEL1_c, and the right eye display unit RD may be disposed along the righteye ellipse EL2_c. Here, the major axis Lax1_c of the left eye ellipseEL1_c and the major axis Rax1_c of the right eye ellipse EL2_c mayoverlap each other. In other words, the major axis Lax1_c of the lefteye ellipse EL1_c and the major axis Rax1_c of the right eye ellipseEL2_c may be disposed on the same line. Thus, the minor axis Lax2_c ofthe left eye ellipse EL1_c and the minor axis Rax2_c of the right eyeellipse EL2_c may be disposed in parallel to each other.

FIG. 9 is a sectional view of a head mounted display device according toanother exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 9, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 9, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD_d, a right eyedisplay unit RD_d, a left eye lens LLS, and a right eye lens RLS.

The left eye display unit LD_d includes a first portion P1_d disposedalong the trajectory of the left eye ellipse EL1 having a major radiusof a and a minor radius of b and a second portion P2_d extending in astraight line.

The second portion P2_d may be disposed to be connected to the firstportion P1_d, and may extend along a straight line tangent to thecontact point of the left eye ellipse EL1 disposed on the boundarybetween the first portion P1_d and the second portion P2_d.

The right eye display unit RD_d includes a third portion P3_d disposedalong the trajectory of the right eye ellipse EL2 having a major radiusof c and a minor radius of d and a fourth portion P4_d extending in astraight line.

The fourth portion P4_d may be disposed to be connected to the thirdportion P3_d, and may extend along a straight line tangent to thecontact point of the right eye ellipse EL2 disposed on the boundarybetween the third portion P3_d and the fourth portion P4_d.

Further, the second portion P2_d of the left eye display unit LD_d maybe disposed closer to the right eye display unit RD_d than the firstportion P1_d of the left eye display unit LD_d, and the fourth portionP4_d of the right eye display unit RD_d may be disposed closer to theleft eye display unit LD_d than the third portion P3_d of the right eyedisplay unit RD_d. In other words, the left eye display unit LD_d andthe right eye display unit RD_d may extend in a straight line betweenthe left eye LE and right eye RE of a user. Thus, the distortion of animage in a region between the left eye and right eye LE and RE of theuser may be minimized.

FIG. 10 is a sectional view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 10, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 10, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD_e, a right eyedisplay unit RD_e, a left eye lens LLS, and a right eye lens RLS.

The left eye display unit LD_e includes a first portion P1_e disposedalong the trajectory of the left eye ellipse EL1 having a major radiusof a and a minor radius of b and a second portion P2_e extending in astraight line. The second portion P2_e may be disposed to be connectedto the first portion P1_e, and may be disposed to overlap the innerregion of the left eye ellipse EL1.

The right eye display unit RD_e includes a third portion P3_e disposedalong the trajectory of the right eye ellipse EL2 having a major radiusof c and a minor radius of d and a fourth portion P4_e extending in astraight line. The fourth portion P4_e may be disposed to be connectedto the third portion P3_e, and may be disposed to overlap the innerregion of the right eye ellipse EL2.

Further, the first portion P1_e of the left eye display unit LD_e may bedisposed closer to the right eye display unit RD_e than the secondportion P2_e of the left eye display unit LD_e, and the third portionP3_e of the right eye display unit RD_e may be disposed closer to theleft eye display unit LD_e than the forth portion P4_e of the right eyedisplay unit RD_e. In other words, in the left edge region of the user'sleft eye LE and the right edge region of the user's right eye RE, theleft eye display unit LD_e and the right eye display unit RD_e may beformed to be bent into the left eye ellipse EL1 and the right eyeellipse EL2, respectively. Thus, the size of the head mount displaydevice may be minimized.

FIG. 11 is a sectional view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 4.

In FIG. 11, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 11, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD_f and a lefteye lens LLS. For the sake of convenience, a description of a right eyedisplay unit and a right eye lens will be omitted, but the descriptionof the left eye display unit LD_f and the left eye lens LLS may besimilarly applied to the right eye display unit and the right eye lens.

The left eye display unit LD_f includes a first portion P1_f disposedalong the trajectory of the first left eye ellipse EL11_f, a secondportion P2_f disposed along the trajectory of the second left eyeellipse EL12_f, and a third portion P3_f disposed along the trajectoryof the third left eye ellipse EL13_f.

The first to third portions P1_f to P3_f may be disposed so as to beconnected adjacent to each other. The first to third left eye ellipsesEL11_f to EL13_f may have major and minor radiuses of different values.In an exemplary embodiment, the first left eye ellipse Ell1_f has amajor radius of a and a minor radius of b, and each of the second lefteye ellipse EL12_f and the third left eye ellipse EL13_f may have amajor radius of a value other than a and a minor axis of a value otherthan b, for example. Moreover, the major axis Lax11_f of the first lefteye ellipse, the major axis Lax12_f of the second left eye ellipse, andthe major axis Lax13_f of the third left eye ellipse may intersect eachother. That is, as described in this exemplary embodiment, the left eyedisplay unit LD_f may be disposed along a plurality of differentelliptical trajectories.

FIG. 12 is a sectional view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 12, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 12, the head mount display device according to thisexemplary embodiment includes a display unit DD_g, a left eye lens LLS,and a right eye lens RLS.

The display unit DD_g includes first to third portions P1_g to P3_g. Thedisplay unit DD_g may be composed of one panel in which a portion incontact with the left eye ellipse EL1 and a portion in contact with theright eye ellipse EL2 are integrated with each other.

Specifically, the first portion P1_g may extend along the trajectory ofthe left eye ellipse EL1 and may display an image. The second portionP2_g may extend along the trajectory of the right eye ellipse EL2 andmay display an image. The third portion P3_g may be a portion that doesnot display an image between the left eye LE and right eye LE and RE ofthe user. In other words, the pixel may not be disposed in the thirdportion P3_g. As such, images may be provided to both the left and righteyes LE and RE of the user through one panel.

FIG. 13 is a sectional view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 3.

In FIG. 13, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 13, the head mount display device according to thisexemplary embodiment includes a display unit DD_h, a left eye lens LLS,and a right eye lens RLS.

The display unit DD_h includes first to fifth portions P1_h to P5_h. Thedisplay unit DD_h may be composed of one panel in which a portion incontact with the left eye ellipse EL1 and a portion in contact with theright eye ellipse EL2 are integrated with each other.

Specifically, the first portion P1_h may extend along the trajectory ofthe left eye ellipse EL1 and may display an image. The third portionP3_h may extend along the trajectory of the right eye ellipse EL2 andmay display an image. The fifth portion P5_h may be a portion that doesnot display an image between the left eye LE and right eye LE and RE ofthe user. In other words, the pixel may not be disposed in the fifthportion P5_h. The second portion P2_h is disposed between the firstportion P1_h and the fifth portion P5_h, extends in a straight line, anddisplays an image. The fourth portion P4_h is disposed between the thirdportion P3_h and the fifth portion P5_h, extends in a straight line, anddisplays an image.

As such, images may be provided to both the left and right eyes LE andRE of the user through one panel, and a part of the display unit DD_hextends in a straight line, so as to minimize the distortion of animage.

FIG. 14 is a sectional view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 2.

In FIG. 14, a description of constituent elements and reference numeralswhich are the same as those described in FIGS. 1 to 5 will be omitted.

Referring to FIG. 14, the head mount display device according to thisexemplary embodiment includes a left eye display unit LD_i, a right eyedisplay unit RD_i, a left eye lens LLS, and a right eye lens RLS.

The left eye display unit LD_i may have a shape curved along thetrajectory of the left eye ellipse EL1 and curved along a directionperpendicular to a plane on which the left eye ellipse EL1 is disposed.More specifically, the left eye display unit LD_i may have a shapecurved along the surface of an ellipsoid including the left eye ellipseEL1.

Similarly, the right eye display unit RD_i may have a shape curved alongthe trajectory of the right eye ellipse EL2 and curved along a directionperpendicular to a plane on which the right eye ellipse EL2 is disposed.More specifically, the right eye display unit RD_i may have a shapecurved along the surface of an ellipsoid including the right eye ellipseEL2.

FIG. 15 is a schematic view of a head mounted display device accordingto another exemplary embodiment at a point corresponding to the point ofFIG. 2, and FIG. 16 is a sectional view of the head mounted displaydevice shown in FIG. 15 taken along a plane on which a left eye ellipseand a right eye ellipse are disposed.

In FIGS. 15 and 16, a description of constituent elements and referencenumerals which are the same as those described in FIGS. 1 to 5 will beomitted.

Referring to FIGS. 15 and 16, the head mount display device according tothis exemplary embodiment includes a left eye display unit LD, a righteye display unit RD, a left eye lens unit LLS_j, and a right eye lensunit RLS_j.

The left lens unit LLS_j includes a first left eye lens LLS1_j and asecond left eye lens LLS2_j. The first left eye lens LLS1_j and thesecond left eye lens LLS2_j may serve to refract an image provided fromthe left eye display unit LD and provide the refracted image to theuser's left eye LE. That is, the first left eye lens unit LLS1_j mayallow the image provided from the left eye display unit LD to beprovided to the user's left eye LE along first to third left opticalpaths LDL1_j to LDL3_j.

When at least one of the first left eye lens LLS1_j and a second lefteye lens LLS2_j is disposed near the first left eye focus LF1 and theleft eye display unit LD is disposed along the left eye ellipse EL1, thevirtual image recognized by the user may be minimized.

Here, the meaning that at least one of the first left eye lens LLS1_jand the second left eye lens LLS2_j is disposed near the first left eyefocus LF1 may mean that at least one of the first left eye lens LLS1_jand a second left eye lens LLS2_j is disposed to overlap the first lefteye focus LF1 on the plane on which the left eye ellipse EL1 isdisposed, at least one of the centroid LC1_j of the first left eye lensLLS_j and the centroid LC2_j of the second left eye lens LLS2_j isdisposed in the first sub left eye ellipse region LSR1, or at least apart of at least one of the two sections of the first left eye lensLLS1_j and the second left eye lens LLS2_j cut by the left eye ellipseEL1 is disposed to overlap the first sub left eye ellipse region LSR1.

The description of the left eye lens unit LLS_j of this exemplaryembodiment may be similarly applied to the right eye lens unit RLS_j.That is, the right eye lens unit RLS includes a first right eye lensRLS1_j and a second right eye lens RLS2_j. The first right eye lensRLS1_j and the second right eye lens RLS2_j may serve to refract animage provided from the right eye display unit RD and provide therefracted image to the user's right eye RE. That is, the right left eyelens unit RLS1_j may allow the image provided from the right eye displayunit RD to be provided to the user's right eye RE along first to thirdleft optical paths RDL1_j to RDL3_j. Further, the virtual imagerecognized by the user may be minimized according to the disposition ofthe right eye lens unit RLS_j.

In this exemplary embodiment, the structure in which each of the lefteye lens unit LLS_j and the right eye lens unit RLS_j includes twolenses has been described, but the invention is not limited thereto.That is, in some exemplary embodiments, each of the left eye lens unitand the right eye lens unit may have a structure including three or morelenses.

As described above, according to embodiments of the invention, it ispossible to provide a head mounted display device, which may minimizethe phenomenon of a virtual image caused by the reflected light due to alens being recognized to a user.

The effects of the invention are not limited by the foregoing, and othervarious effects are anticipated herein.

Although the preferred embodiments of the invention have been disclosedfor illustrative purposes, those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the invention as disclosed in theaccompanying claims.

What is claimed is:
 1. A head mounted display device, comprising: adisplay unit including a first portion which displays an image for aleft eye and is disposed along a trajectory of a left eye ellipse havinga first eccentricity, a second portion which displays an image for aright eye and is disposed along a trajectory of a right eye ellipsehaving a second eccentricity, and a third portion between the firstportion and the second portion; a left eye lens which faces the firstportion and refracts the image for the left eye in a direction of auser's left eye; and a right eye lens which faces the second portion andrefracts the image for the right eye in a direction of a user's righteye.
 2. The head mounted display device of claim 1, wherein the left eyeellipse defines a first left eye focus and a second left eye focus, andthe left eye lens overlaps at least one of the first left eye focus andthe second left eye focus on a plane on which the left eye ellipse isdisposed.
 3. The head mounted display device of claim 2, wherein thefirst left eye focus is disposed closer to a user's right eye than thesecond left eye focus, and the left eye lens overlaps the first left eyefocus on the plane on which the left eye ellipse is disposed.
 4. Thehead mounted display device of claim 2, wherein the left eye ellipse isdivided by a major axis of the left eye ellipse, and wherein the firstleft eye focus and the second left eye focus are on the major axis ofthe left eye ellipse.
 5. The head mounted display device of claim 1,wherein the left eye ellipse is divided by a major axis of the left eyeellipse, and includes a first left eye ellipse region adjacent to thedisplay unit and a second left eye ellipse region spaced apart from thedisplay unit, the second left eye ellipse region is divided by a minoraxis of the left eye ellipse, and includes a first sub left eye ellipseregion disposed near the display unit and a second sub left eye ellipseregion disposed away from the display unit, and the left eye lens has acentroid disposed in the first sub left eye ellipse region.
 6. The headmounted display device of claim 1, wherein the left eye ellipse isdivided by a major axis of the left eye ellipse, and includes a firstleft eye ellipse region adjacent to the display unit and a second lefteye ellipse region spaced apart from the display unit, the second lefteye ellipse region is divided by a minor axis of the left eye ellipse,and includes a first sub left eye ellipse region disposed near thedisplay unit and a second sub left eye ellipse region disposed away fromthe display unit, and at least a part of the left eye lens overlaps thefirst sub left eye ellipse region on a plane on which the left eyeellipse is disposed.
 7. The head mounted display device of claim 1,wherein the first eccentricity and the second eccentricity have the samevalue.
 8. The head mounted display device of claim 1, wherein the thirdportion does not display the image for the left eye and the image forthe right eye.
 9. The head mounted display device of claim 1, whereinthe left eye ellipse and the right eye ellipse partially overlap eachother.
 10. The head mounted display device of claim 1, wherein the majoraxis of the left eye ellipse and the major axis of the right eye ellipseintersect each other.
 11. The head mounted display device of claim 1,wherein the left eye display unit is disposed to be spaced apart fromthe major axis of the left eye ellipse.